Neumann has essentially produced two U87's. The first manufactured from 1967-1986 is the U87(i) which is commonly referred to as a vintage U87, and the second built from 1986-present, U87Ai.
There are a few variants within each version. These are detailed with pictures and description below.
The U87i was built from 1967-1986. The 'i' in U87i indicates it had an international connector, that is a 3-pin XLR connector. It came in nickel (ni) and matte-black (mt) finish.
The U87 was built from 1967-1986. The U87i is commonly referred to as a U87, however strictly speaking the U87 has a 7-Pin Tuchel connector. It came in nickel (ni) and matte-black (mt) finish. Approximately 50,000 U87(i) were built.
Neumann U87, U87i internal componenets.
The U87Ai came into production in 1986, the same year U87(i) ceased production. The microphone is still in production. It comes in nickel (ni) and matte-black (mt) finish.
U87Ai Neumann 70th Anniversary Edition
Neumann released a gold U87Ai in 1998 to celebrate its 70th year of establishment. Approximately 300 were made, and all came complete with flight case and gold shockmount.
U87Ai 40th Anniversary Edition
Neumann released a special edition of the U87Ai in 2007. It marks the 40th anniversary of the U87. A total of 1000 were produced and all came complete with shockmount, popshield and flight case.
Neumann U87Ai internal components